In existing liquid crystal display panels, a Color filter On Array (COA) technology has been known, which can improve an aperture opening ratio of the liquid crystal display panels so as to improve brightness and image quality of the liquid crystal display panels. A manufacturing process of such an array substrate includes steps of: S1: forming an alignment mark and a thin film transistor on a surface of a base substrate, and forming a first isolation layer on the alignment mark, the thin film transistor and the base substrate; S2: coating a black matrix material on a surface of the first isolation layer to form a black matrix material film, i.e., covering the alignment mark with the first isolation layer and the black matrix material film, so that the alignment mark is covered by the first isolation layer and the black matrix material film and the position of the alignment mark cannot be displayed; and S3: by an exposure machine, carrying out alignment according to the alignment mark and carrying out exposure on the black matrix material film to form a black matrix pattern aligned with other patterns in previous processes. Alignment between the existing exposure machine and the alignment mark adopts a light transmission mode. Due to high optical density of the black matrix material film, the exposure machine cannot clearly identify the alignment mark under the black matrix material film.